Gas Sales Agreements are usually priced on a GJ basis, it states it is a fixed price with index for inflation. Articles out today show the market price for east coast gas in AUD is anywhere between $8 - $14. Lets assume the low side of $8/GJ. Total contract size is 3.25PJ
3,250,000 x $8 = $26 Million
That is the very simple calculation without factoring anything else in.